Skip to Main content Skip to Navigation

Catabolisme des agars chez Zobellia galactanivorans

Abstract : Agars are red algal polysaccharides. These are composed of D-galactose with L-galactose alterned by glycosidic bond -1,4 and -1,3. These galactans harbor several modifications : sulfatations, methylations, pyruvylations. All these modifications hinder the agar degradation by marine bacteria. Zobellia galactanivorans is a marine flavobacterium able to degrade marine polysaccharides, including agars. The aims of this thesis are to identify and characterize the enzymatic tools of Z. galactanivorans to degrade the complex agar. The two subjects are a divergent -agarase (ZgAgaC) and sulfatases that act on agars. To perform this study on the agar specific enzymes, we have developed activity screens on a complex agar collection of substrates produced during the thesis. These screens have been used to show the divergent behaviour of ZgAgaC on complex agar compared to the other -agarases and -porphyranases of the family 16 (GH16). These screens were further used to identify the substrate of two sulfatases active on agar. To conclude, this work has allowed to develop different tools to identify new enzymatic activities and to have a better view of the agar catabolism of Z. galactanivorans.
Complete list of metadatas
Contributor : Abes Star :  Contact
Submitted on : Monday, November 23, 2020 - 1:03:20 AM
Last modification on : Tuesday, November 24, 2020 - 3:28:19 AM


Version validated by the jury (STAR)


  • HAL Id : tel-03018586, version 1


Anaïs Naretto. Catabolisme des agars chez Zobellia galactanivorans. Biochimie [q-bio.BM]. Sorbonne Université, 2018. Français. ⟨NNT : 2018SORUS498⟩. ⟨tel-03018586⟩



Record views